This invention relates generally to a system for monitoring and controlling the amount of dissolved oxygen (D.O.) in a pool or plurality of pools employed for treating sewerage or for farming marine life such as fish, or the like, and more particularly to an automated system for simultaneously and automatically maintaining the amount of D.O. individually in each of a plurality of such pools and to promptly and sequentially inform up to N predetermined people by a recorded telephone message transmitted by an automated telephone of the decrease of the amount of D.O. in any specific pool below a predetermined threshold until one of the callers answers his telephone and phones a predetermined code back to the automated telephone, followed up by a having a maintenance worker investigate and repair the ameliorate problem.
There are a number of working prior art devices for manually maintaining the desired amount of D.O. in a pool. Virtually all of these prior art systems employ some stirring type of device which, when activated, will increase the amount of D.O. in a pool. Such a stirring type device can be a submergible air pump, a paddle wheel, bank washers, root blowers or a hollow shaft pump, all in accordance with the National Fire Underwriters' Electrical code, although other devices are available. Some prior art devices also contain D.O. measuring probes which are immersed in the pool and measure the amount in suitable units, such as part per million (PPM), of D.O. in the pool and transmit signals to a meter which show the measured amounts of D.O.
However, there is no centrally located control which will automatically and continuously monitor the amount of D.O. in either a single pool or a plurality of pools. These prior art systems require periodic inspection by a human operator who must come to each pool and read the amount of D.O. which is being energized by the signals from the probe. If the amount of D.O. is too low the human operator must take the necessary steps to raise the amount of D.O. above the minimum allowed threshold, usually by activating the stirring or aerator device. If something more serious is involved then the human operator must take the necessary steps to repair the problem immediately or the fish in the pool will die, which can represent a financial loss running into several tens of thousands of dollars.
The foregoing systems have obvious, serious risks since a problem can develop in a given pool within five minutes after the last inspection and if the amount of D.O. in that pool drops fast enough and far enough all the fish in that pond will die before the next scheduled inspection occurs.